Just recently, NYTimes.com and Twitter became the latest victims of cyber attacks that left their websites unavailable for hours. As these kinds of attacks become more prevalent and attackers' methods more advanced, George Mason University researchers are at the forefront of thwarting the efforts of these assailants.

Leading a team of researchers, Sushil Jajodia, director of George Mason's Center for Secure Information Systems (CSIS), which is housed in the Volgenau School of Engineering, recently received a five-year, $6.25 million grant from the Department of Defense to develop adaptive defenses against attackers.

Researchers from the Center for Secure Information Systems -- Kun Sun, center director and principal investigator Sushil Jajodia, and Massimiliano Albanese, recently received a five-year, $6.25 million grant from the Department of Defense to develop adaptive defenses against attackers.

Jajodia will work with co-principal investigators Massimiliano Albanese, an assistant professor in CSIS; Kun Sun, a research professor in CSIS; and researchers from three other universities — Dartmouth College, Pennsylvania State University and the University of Michigan.

The project will develop a new class of technologies called Adaptive Cyber Defense, which will force adversaries to continually re-assess, re-engineer and relaunch their cyber attacks.

Jajodia compares the tactics of a cyber attacker to those used by the military during warfare. Attackers, he says, do reconnaissance before an attack by scoping out their targets, which are typically computer networks of individuals or entire organizations.

The problem with current network defenses used today — firewalls and other intrusion detection systems — is that they are largely static. Therefore, attackers only need to create one successful attack strategy to infiltrate the system. Jajodia and his colleagues want to make things harder for adversaries. He likens the approach to shooting at a moving target, as opposed to a stationary one.

"It is much easier for attackers to identify the weak spots and create attack plans that can take down an entire system in networks that use only one defense mechanism," says Jajodia. "To successfully defend our networks, we must be strategic and employ tactics of maneuvering and movement that constantly keep the attackers guessing."

For example, Sun notes that to keep attackers on their toes, an individual might choose to change the Internet Protocol (IP) address on a computer. An IP address is a numerical label assigned to each device in a computer network. A constantly changing IP address makes it more difficult for an assailant to attack the system.

This strategy, however, also has its drawbacks. According to Albanese, if the IP address is constantly in flux, it becomes harder for a legitimate user to successfully use the system. "Determining how we can thwart an attacker's reconnaissance efforts while allowing the system to operate seamlessly for legitimate users is one of the challenges we will be trying to solve as we continue working on this project," says Albanese.

However, addressing security vulnerabilities of a network system is only half the battle. An important part of this process, Jajodia notes, is to understand the behavior of the adversary. To get into the minds of these sophisticated attackers, who are intent on stealing everything from credit card numbers to military secrets, the researchers will devise a series of models that will help them anticipate an attacker's next moves.

"To the experienced cyber criminal, the act of taking down an entire network system is very much a game between the defender and attacker," says Jajodia. "As researchers, it is our job to understand and even set the rules of this game so that we can outsmart the attackers before they have the opportunity to create severe damage."

Out of 193 white papers submitted, which were followed by 43 proposals, Mason was one of 15 academic institutions awarded a grant to perform multidisciplinary basic research. The awards are part of an annual competition conducted by the Army Research Office, the Air Force Office of Scientific Research, and the Office of Naval Research under the Department of Defense Multidisciplinary University Research Initiative (MURI) Program. The MURI program supports research by teams of investigators that intersect several traditional science and engineering disciplines.

A version of this story appeared on the Mason News Desk October 16, 2013.